Junior
What is a relational data model?
sobes.tech AI
Answer from AI
A relational data model is a way of organizing data into tables called relations. Each table consists of rows (tuples) and columns (attributes).
Key concepts:
- Relation (Table): A set of tuples of the same type.
- Tuple (Row): A single record representing an instance of an entity.
- Attribute (Column): A property of the entity, represented as a named column.
- Domain: A set of permissible values for one or more attributes.
- Primary Key: One or more attributes that uniquely identify each tuple in a relation.
- Foreign Key: One or more attributes in one relation that reference the primary key of another relation, establishing a link between tables.
- Relationships between tables: Established using foreign keys and can be of types:
- One-to-One
- One-to-Many
- Many-to-Many
Advantages:
- Logical simplicity and clarity of data structure.
- Strict data integrity rules.
- Support for declarative query language (SQL).
- Easy to scale and modify.
Disadvantages:
- Complexity in representing hierarchical and network data structures without decomposition.
- Possible data redundancy due to insufficient normalization.